The invention relates to a luminaire with light guiding surfaces.
The term xe2x80x9cluminairexe2x80x9d means an apparatus designed such that it can emit light generated by a light source, e.g. a fluorescent tube or an incandescent bulb, essentially without glare.
In a preferred embodiment, light is emitted without glare xe2x80x9cdirectlyxe2x80x9d into the room to be illuminated or at a location to be illuminated.
However, with the luminaire according to the invention, light from the light source can be emitted xe2x80x9cindirectlyxe2x80x9d into the room to be illuminated or at the location to be illuminated by the light being radiated toward a ceiling or a wall of the room. From there, it is reflected into the room to be illuminated or at the location to be illuminated.
The embodiments of the invention which are illustrated herein are designed such that they emit xe2x80x9cdirectxe2x80x9d light downward and xe2x80x9cindirectxe2x80x9d light upward.
For generating light without glare, EP 0495273 B1 discloses a flat luminaire having a transparent plate. The plate has a flat top side and a top side provided with prism-like ribs. The light passes through the plate and through the prism regions thereof. It is multiply refracted in the prism regions in the process.
U.S. Pat. No. 5,555,329 discloses a light guiding structure having an optical waveguide plate. Prism blocks are either formed or placed on a surface of the optical waveguide plate, so that light can penetrate the prism block from the optical waveguide plate and then, after repeated light refraction, can emerge from the prism block into the external surroundings.
Similar luminaires, specifically for background lighting, are also shown by U.S. Pat. No. 5,396,350 and WO 97/26584, DE 43 42 338 A1, DE 43 01 339 A1, DE 43 39 274 A1.
The invention is intended to achieve the object of providing a luminaire for light without glare which acts similarly to the known luminaires having prism blocks but which can be produced significantly more cost-effectively, structurally more simply and with a smaller structural height.
This object is achieved according to the invention by the luminaire having an optical waveguide, with opposite light guiding surfaces, a transverse light introducing area; a first reflecting area comprised of obliquely arranged reflecting areas reflecting light back through the waveguide through the other surface along with non-reflected light which passes through the waveguide. Glare is essentially avoided.